This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-232779, filed Aug. 19, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a probe card used in a probe card apparatus used for inspecting the electrical characteristics of a target body to be inspected and a method of manufacturing the same.
The probe apparatus for an integrated circuit formed on a semiconductor wafer W includes generally a loading chamber 91 and a probing chamber 92, as shown in FIGS. 12 and 13. The wafer W is transferred and pre-aligned in the loading chamber 91. The wafer W is transferred from the loading chamber 91 into the probing chamber 92, and the electrical characteristics of the integrated circuits formed on the wafer W are inspected in the probing chamber 92. Tweezers 93 and a sub-chuck 94 are arranged within the loading chamber 91. While the wafer W is being transferred by the tweezers 93, the wafer W is pre-aligned by the sub-chuck 94 on the basis of the orientation flat or a notch of the wafer W. A main chuck 95 and an alignment mechanism 96 are arranged within the probing chamber 92. The main chuck 95 having the wafer W disposed thereon is moved in the X, Y, and xcex8 directions and co-operates with the alignment mechanism 96 to align the wafer W with probes 3 of a probe card 97 arranged above the main chuck 95. The main chuck is moved upward in the Z-direction so as to bring the wafer W into an electrical contact with the probes 3. As a result, the electrical characteristics of the integrated circuit formed on the wafer W are inspected through the probes 3 and a test head T.
The probe card 97 is brought into contact with electrode pads of the IC chips so as to relay the exchange of an inspecting signal between the tester and the IC chips. The probe card is provided with a plurality of probes of a wire type arranged to correspond to, for example, a plurality of electrode pads formed on the IC chips.
In recent years, the degree of integration of the IC chip is increased, and the number of electrode pads is on a sharp increase. Also, the arranging pitch of the electrode pads is made smaller and smaller. As a result, the number of probes of the probe card is also on a sharp increase, and the probes are arranged at a smaller pitch. With increase in the diameter of the wafer, the number of IC chips within the wafer is also on a sharp increase. As a result, a long time is required for inspecting these IC chips. It is of high importance to shorten the time required for the inspection. Such being the situation, the number of IC chips that are inspected simultaneously is increased in an attempt to shorten the inspecting time. As a prove card for dealing with the increase in the number of probes and with the increase in the number of IC chips that are to be inspected simultaneously, known is a membrane type probe card having bump-shaped probes. The probes of the probing card of this type can be integrated to a high integration degree to conform with the miniaturized IC chips. However, the probing card of this type is defective in that the probe itself lacks an elasticity. If the probes are integrated to a high integration degree, the clearance between the adjacent probes is unduly small, with the result that the membrane fails to follow the difference in height among the various electrode pads formed on the IC chip. It follows that it is difficult for the probe to be brought into stable contact with the electrode pad on the IC chip.
The present invention is intended to overcome the difficulty described above.
An object of the present invention is provide a probing card capable of dealing with the difficulty that the electrode pads of the element are integrated to a high integration degree and the pitch between the adjacent electrodes is diminished because of the increased degree of integration of the elements and the increase in the number of target objects to be inspected simultaneously.
Another object of the present invention is to provide a probe card that permits all the probes to be brought into contact with the corresponding electrode pads even if the electrode pads are not uniform in height.
Another object of the present invention is to provide a probe card that permits performing inspection of a high reliability by achieving at least one of the objects described above.
Another object of the present invention is to provide a method of manufacturing a probe card that permits collectively forming probes corresponding electrode pads even if the electrode pads of the element are integrated to a high integration degree to make the arranging pitch of the electrode pads smaller.
Further, still another object of the present invention is to provide a method of manufacturing a probe card at a low manufacturing cost.
The other objects and advantages of the present invention will be described herein later and a part thereof is obvious from the disclosure herein or may be obtained by the practice of the present invention. These objects and advantages of the present invention may be realized by the combination of the particular means pointed out herein.
According to a first aspect of the present invention, there is provided a probe card having a plurality of probes that are brought into contact with at least one element formed on a target object to be inspected for inspecting the electrical characteristics of said element, said probe comprising:
a thin film-like base section formed along the lower circumferential surface of an imaginary pyramid having at least a pyramidal top portion;
a contact terminal section formed along the outer circumferential surface of the top portion of said imaginary pyramid; and
at least one thin film-like joining section having a predetermined shape and serving to join said contact terminal section to said base section.
It is desirable for said joining section of at least one of said plural probes of the probe card to be shaped spiral such that the joining section extends from the base section to the contact terminal section along the outer circumferential surface of the imaginary pyramid.
It is also desirable for said joining section of at least one of said plural probes of the probe card to be shaped linear such that the joining section extends from the base section to the contact terminal section along the outer circumferential surface of the imaginary pyramid.
It is also desirable for the base section of the probe card to be formed frame-like along the entire circumferential surface at the lower portion of the imaginary pyramid.
It is also desirable for the plural probes of the probe card to have their shapes selected in accordance with the positions of the probe card at which these probes are arranged.
According to a second aspect of the present invention, there is provided a method of manufacturing a probe card provided with a contactor having a plurality of probes of predetermined shapes that are brought into contact with at least one element formed in a target object to be inspected for inspecting the electrical characteristics of said element, comprising the steps of:
(a) forming a plurality of concave portions on the surface of a substrate, said concave portions being arranged to conform with said probes and shaped pyramidal in at least the top portions;
(b) filling a molding material in each of said concave portions, followed by solidifying the molding material so as to form a plurality of molded bodies having at least the top portions shaped pyramidal;
(c) transferring each of the molded bodies formed on the substrate onto the electrodes arranged on said contactor;
(d) forming an underlying metal thin film on the outer circumferential surface of every molded body transferred onto the contactor
(e) forming a resist film on the underlying metal thin film formed on the outer circumferential surface of the molded body;
(f) removing that portion of the resist film formed on the underlying metal thin film in which said probe is to be formed;
(g) forming a conductive metal thin film for forming a probe on the outer circumferential surface of the molded body; and
(h) removing the resist film remaining on the molded body, the metal thin film formed on the resist film for forming the probe, at least that portion of the underlying metal thin film which is positioned below the resist film, and the molding material.
In the manufacturing method of the probe card of the present invention, it is desirable for the plural probes to have a base section, a contact terminal section, and a joining section for joining the base section and the contact terminal section. It is also desirable for the joining section to be shaped spiral and to extend from the base section to the contact terminal section along the outer circumferential surface of the molded body.
In the manufacturing method of the probe card of the present invention, it is desirable for the plural probes to have a base section, a contact terminal section, and a joining section for joining the base section and the contact terminal section, and also desirable for the joining section to be shaped linear and to extend from the base section to the contact terminal section along the outer circumferential surface of the molded body.
In the manufacturing method of the probe card of the present invention, it is desirable for the plural probes to comprise a base section, a contact terminal section and a joining section for joining the base section and the contact terminal section, and also desirable for the base section to be formed frame-like along the entire outer circumferential surface in the lower portion of the molded body.
According to a third aspect of the present invention, there is provided a method of manufacturing a probe card provided with a contactor having a plurality of probes of predetermined shapes that are brought into contact with at least one element formed in a target object to be inspected for inspecting the electrical characteristics of said element, comprising the steps of:
(a) forming a plurality of concave portions on the surface of a substrate, said concave portions being arranged to conform with said probes and shaped pyramidal in at least the top portions;
(b) forming a conductive metal thin film for forming the probe on the surface of each of said concave portions so as to form a plurality of probe members each having at least the top portion shaped pyramidal;
(c) transferring the probe members formed in the concave sections onto a plurality of electrodes arranged on the contactor; and
(d) applying a laser processing to said probe member so as to form a probe having a predetermined shape.
In the method of the present invention for manufacturing the probe card, it is desirable for the conductive metal thin film for forming the probe member to be formed in said step (b) after formation of a thin film for peeling said probe member on the surface of each of said concave portions.
In the method of the present invention for manufacturing the probe card, it is desirable for said step (c) to include the process of removing the thin film for peeling with a solution so as to peel the probe member from the concave portion.
In the method of the present invention for manufacturing the probe card, it is desirable for said step (b) to include the process, after formation of a conductive metal thin film for forming a probe on the surface of each concave portion, of forming a metal thin film for forming the probe in the peripheral portion of the concave portion and of forming a conductive metal thin film for fixation for improving the bonding strength between the conductive metal thin film and each of the plural electrodes arranged on the contactor.
In the method of the present invention for manufacturing the probe card, it is desirable for each of the probes to have a base section, a contact terminal section and a joining section for joining the base section and the contact terminal section and also desirable for the joining section to extend from the base section to the contact terminal section along the outer circumferential surface of the probe member and to be shaped spiral.
In the method of the present invention for manufacturing the probe card, it is desirable for each of the probes to have a base section, a contact terminal section and a joining section for joining the base section and the contact terminal section and also desirable for the joining section to extend from the base section to the contact terminal section along the outer circumferential surface of the probe member and to be shaped linear.
Further, in the method of the present invention for manufacturing the probe card, it is desirable for each of the probes to have a base section, a contact terminal section and a joining section for joining the base section and the contact terminal section and also desirable for the base section to be formed frame-like along the entire outer circumferential surface in a lower portion of the probe member.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.